Esters of oxydicarboxylic acids and cyclic alcohols



United States Patent 3,113,963 ESTERS 0F OXYDICARBOXYLIC ACIDS AND CYCLIC ALCOHOLS John R. Caldwell and Winston J. Jackson, Jr., Kingsport,

Tenn, assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey No Drawing. Filed Jan. 16, 1962, Ser. No. 166,7 03 7 Claims. (Cl. 260-473) This invention relates to novel esters and more particularly to esters of oxydicarboxylic acids and cyclic alcohols containing a ring bridgehead and gem dialkyl groups adjacent to a secondary hydroxy group.

An object of the invention is to provide esters that are new compositions of matter. Another object is to provide a method of preparation of the esters of oxydicarboxylic acids and cyclic alcohols. A further object is to provide esters of oxydicarboxylic acids having good hydrolytic stability, which are useful as plasticizers for poly(vinyl chloride), cellulose ethers, celllulose esters and the like.

Esters of oxydicarboxylic acids and various aliphatic alcohols are known. However, esters of these acids have a serious drawback that limits their utility. Typical esters of the oxydicarboxylic acids are readily hydrolyzed by boiling water. In accordance with the present invention we have now developed novel esters of oxydicarboxylic acids which have excellent hydrolytic stability. We are thus able to benefit from the advantages of using the oxydicarboxylic acids while avoiding the poor hydrolytic stability that has heretofore characterized esters of such acids.

The novel esters are prepared in accordance with the invention by heating an oxydicarboxylic acid with a cyclic alcohol containing a ring bridgehead and gem dialkyl groups adjacent to a secondary hydroxy group at a temperature, for example, of 150 to 250 0, preferably in the presence of a metallic esterification catalyst and a volatile, inert organic solvent that forms an azeotrope with water distilling at the reaction temperature.

The oxydicarboxylic acids employed in accordance with the invention are acids of the type wherein R is a divalent organic radical such as CH Patented Dec. 10, 1963 wherein R is hydrogen or a methyl or ethyl radical and R and R are straight or branched chain alkyl radicals of from 1 to 4 carbon atoms.

The three types of alcohols above have in common the fact that they are bicyclic compounds having a secondary hydroxy group adjacent to one of the bridgehead carbon atoms and also adjacent to another carbon atom having gem dialkyl substituents.

Fenchyl alcohol, an alcohol of type I in which all of the Rs are methyl groups, is a well known alcohol and is available commercially. The alcohols of type II can be obtained by reducing unsaturated ketones of the types described in the patent to Kealy, US. 2,883,425. Such ketones are of the type:

Uma ao H H OH R2 2 R2 [1 The novel esters are prepared in accordance with the invention by heating the oxydicarboxylic acid, the cyclic alcohol (preferably, in slight excess over two mols per mol of acid) and a small amount of catalyst with a small amount of azeotroping agent. In the preferred procedure of the invention the water evolved in the reaction is collected in a Dean-Stark trap filled with the azeotroping solvent. The volume of the water layer in the trap indicates the degree of completion of the reaction.

The reaction will proceed slowly in the absence of a catalyst but the use of a catalyst is greatly preferred in order to achieve a satisfactory reaction rate. The preferred catalysts are metallic esterification catalysts. Examples of these include titanium alkoxides such as titanium tetraa a isopropoxide and other alkoxides of titanium prepared CH3 CH3 from lower alkanols, i.e., aliphatic monohydroxy altco- H H hols of one to about four carbon atoms. Various ot er \l l/ organo-titanium compounds are also suitable catalysts as E JHl (IJ OOCCHZ O*CHQ COO (IJ 2 I 2 21120 well as titanium oxides and hydroxides. Such catalysts 5 CH: I C-CH; H3043 I CH2 are described in the patents to Caldwell, US. 2,727,881 and US. 2,720,502; Haslam, U.S.d2,88522,134(2); anrti1 Blritish Difcnchyloxydiacetate Patents Nos. 852,109, 851,600 an 2, 1 T e atter v two patents also disclose suitable organo-zirconium esteri- 8 3 ggf y gg gi 5:3 5532i fication catalysts. Still other suitable metallic esfjerifica- 1O R2 and 1 g f titanium tetration catal sts include various organo-tin com oun s, e.g., tin alkoxi des, tetraalkyl tin compounds, etc. as disclosed lsopropomde. and m of p'cymene was refluxed l 4 in British Patent No. 810,381 and German Patent No. hours During fins 9 of Water collected In a 1,005,947; lead oxide, sodium aluminate, manganese ace- Deanfsbark trap filled wl'th p'cymene and smiled to the tate and the like. As we have indicated, only a small reactlon a T e product was taken up m benzene and amount of catalyst is required, from about 0.1 to 2 Washed with sodium brcarbonate solution and water. weight percent of the reaction mixture. Larger amounts dlymg g Sodlum f the 35 g i of catalyst can be used but no advantage is thereby gained. centrated' T 6 last traces 0 so Vent excess c0 0 While the described metallic esterification catalysts are were removed at 150 0/51 T greatly preferred as catalysts for the method of the inven- The Product Example 1 was sllblec'wd to a bol mg tion, acidic esterification catalysts, e.g., sulfuric acid, hy- Water hydrolysls test C refluxmg Water 96 drochloric acid, B'F etc. can be used. However, if an hours sflmple lequlred 0272 of alkah to acidic esterification catalyst is used, dehydration and reneutrahze the aclld formed Therefore the Sample was arrangement of the cyclic alcohol can take place instead 5% g g t f h v f E 1 1 d The esterifioation reaction is preferably carried out in z j fg i gi a g g g 2: In a the presence of a volatile, inert, organic liquid that forms similar manner poly (vinyl dhorildc) vvas plasticize yield an azeotrope with water that distills at the desired reaction ing a C16 l flexible tough Sheet. temperature in the range of about 150 to 250 C. The 9 preferred reaction temperature is in the range of 180 to Example 2 200 C. and the preferred azeotroping agent for this reaction temperature is p-cymene. Other azeotroping agents such as benzene, toluene, cumene, etc. can be used. How- Ji HOOCCH2 O CHZCOOH ever, with the lower boiling liquids the reaction Itempera- CHI! A ture is lower and the reaction time is longer. OH-O (02m),

The esters of our invention are valuable as plasticizers 3,3-diethylblcyclo- Oxydiacetlc acid for poly(vinyl chloride), cellulose ethers and cellulose lz'lflman'zll esters such as cellulose acetate propionate and cellulose g acetate butynate, all of which can be processed on hot 40 rolls. The ester is normally employed in an amount of fi (IJHZ E 21.120 about 25 to 100 parts by weight per 100 parts of resin. CH2 CH1 CH3 Our novel esters are particularly valuable as plasticizers OHC(C2H5)Z ((hHmC CH because they are highly resistant to hydrolysis and can be Bis(3,3-diethylbicyclo[2.2.2]octanused in molded articles and films under humid conditions 2'ynoxydlacemte that would cause hydrolysis of conventional plasticizers. y y Omani-01 (alcohol of yp II The following examples illustrate features of the invenin which R1 is hydrogen and R3 are ethyl radicals) tion. was prepared by reducing 3,3-diethylbicyclo[2.2.2]cot-5- r0 en-2-one (described in Example 1 of US. 2,883,425) with Example 1 hydrogen at 1500 p.s.i. and 150 C. over a nickel catalyst (Girdler G-49). The cyclic alcohol was thereafter esterified with oxydiacetic acid according to the procedure of 0 H Example .1. CH2 cat After 96 hours in boiling water, a sample of the ester HOOGCI-IzO-CHr-OOOH +2| 0H I of Example 2 was only 3.1% hydrolyzed. The ester 0H1 3-C a A plasticized cellulose acetate propionate and poly(vinyl CH CH: chloride) when milled on heated rolls in the manner pre- Oxydiacetic acid Fenchyl alcohol viously described.

Example 3 C COH Cfiz CH2 cat. HOOCCHnO(CH2)4O-CH2COOH 2] l CH2 CH3 A C C 2 92 Tetramethylenedioxydiacetic acid 1,3 3-triethy1bicyclo f2.2.2]oetan-2-ol (IJzHt H H C2H5 /CCOOCCHzO(OH2)4O-CHzOOOC-C CH: CH; C14: CHz

l EH20 CH2 CH2 CH2 CH2 CH-C (C2115): (C2H5)2C CH Bis (1,3,3-triethylbicyclo[2.2.2]0etan-2-yl) tetramethylenedioxydiacetate 1,3,3-triethylbicyclo[2.2.2]octan-2-o1 (a type II alcohol in which all Rs are ethyl groups) was prepared by reduction of 1,3,3-triethylbicyclo[2.2.2]oct--en-2-one (Example 1 of U.S. 2,883,425) by the method of Example 2. Esterification of tetramethylenedioxydiacetic acid with this cyclic alcohol was carried out as in Example 1.

After 96 hours in boiling water a sample of the ester of Example 3 was only 3% hydrolyzed. This ester plasticized cellulose esters, cellulose ethers and polyat 150 C. and 1500 p.s.i. of hydrogen. The hydrogenation product was 7,7-dimetl1ylbicyclo[3.2.0]heptan-6-ol, which is an alcohol of type III in which R and R are methyl radicals. The alcohol was esterified with oxydiacetic acid by the procedure of Example 1 to obtain the novel ester.

After 96 hours in boiling water a sample of the ester of Example 4 was only 1.5% hydrolyzed. This ester plasticized cellulose esters, cellulose ethers and poly- (vinyl chloride) when milled on heated rolls as in Ex- (vinyl chloride) when milled on heated rolls as previousample 1.

1,3-Phenylenedioxydiacetic acid I CH2 ly described.

7,7-methylethylbicycl0 CHs-C-CH:

C 11 CH2 Bis (7,7-methy1ethylbicyclo [3.2.0] heptan-6-y1) 1,3-pheny1enedloxydiacetate Ethylenedioxydiacetic acid The ester product of this example was prepared by esterifying 7,7-methylethylbicylo[3.2.01heptan-6-ol (a type III alcohol in which R is methyl and R is ethyl) with 1,3-phenylenedioxydiacetic acid according to the procedure of Example 1. The cyclic alcohol was obtained by the reaction of methylethylketene with cyclopentadiene followed by hydrogenation of the resulting unsaturated ketone, substantially according to the procedure of Ex ample 4.

In the hydrolysis test of the ester of Example 5, after 96 hours in boiling water a sample of the ester was only 1.3% hydrolyzed. The ester plasticized cellulose esters, cellulose ethers and poly(vinyl chloride) when milled on heated rolls as previously described.

Example 6 7,7-ethylbutylbicyclo [3.2.0]heptan-6-ol 7,7 dimethylbicyclo[3.2.0]hept-3-en-6-one was prepared by the addition of cyclopentadiene to dimethylketene by a procedure similar to that of Staudinger and Meyer, Helv. Chim. Acta, 7, 21 (1924). Our procedure was to form a solution of 340 g. of cyclopentadiene in 1500 ml. of hexane in a reaction vessel. Dimethylketone vapor was passed into the solution continuously over a period of 7 hours, the reaction mixture being maintained at 6 to 12 C. by an ice bath. Additional portions of cyclopentadiene were added to the reaction vessel during the period of 7 hours, the total amount being 1500 g. including the initial 340 g. The reaction mixture was allowed to stand overnight and then low boilers were distilled off up to 34 C. at 7 mm. Hg and the residue was recovered as the unsaturated ketone product. The latter The ester product of this example was prepared by esterifying 7,7-ethylbutylbicyclo[3.2.0]heptan-6-ol with ethylenedioxyacetic acid according to the procedure of Example 1. The cyclic alcohol was obtained by the reaction of ethylbutylketene with cyclopentadiene followed by hydrogenation of the resulting unsaturated ketone, sub stantially according to the procedure of Example 4.

In the hydrolysis test of the ester of Example 6, after 96 hours in boiling water a sample of the ester Was only 0.6% hydrolyzed.

We have indicated the excellent hydrolytic stability of the esters of oxydicarboxylic acids in accordance with the invention, showing that in hydrolytic tests typical esters of our invention were only 0.6 to 5.5% hydrolyzed after 96 hours in boiling water. In contrast, similar tests of was thereafter reduced over Girdler G49 nickel catalyst other oxydicarboxylic acids show poor hydrolytic stability.

7 For instance, the oxydiacetate of 2-norcamphanol was 63% hydrolyzed after 96 hours in boiling water and the oxydiacetate of Z-ethylhexanol was completely hydrolyzed under these conditions.

The invention has been described in considerable detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected Within the spirit and scope of the invention as described hereinabove, and as defined in the appended claims.

We claim:

1. A diester of (a) an oxydicarboxylic acid of the formula wherein R is a divalent radical of the group consisting of --CH and {-CH OCH wherein x is an integer from and i j 1 l CIIr-CH( }OH 311, (|)H(!J-R1 CH2 R3 III wherein R is selected from the group consisting of hydrogen, methyl and ethyl, and R and R are alkyl of 1 to 4 carbon atoms. 2. Difenchyl oxydiacetate. 3. Bis(3,3 diethylbicyclo[2.2.2]octan 2 yl)oxydiacetate.

4. Bis(1,3,3 triethylbicyclo[2.2.2]octan 2 yl)tetramethylenedioxydiacetate.

5. Bis(7,7 dimethylbicycle[3.2.0]heptan 6 yl)oxydiacetate.

6. Bis(7,7 methylethylbicyclo[3.2.0]heptan 6 y1)- 1,3-pheny1enedioxydiacetate.

7. Bis(7,7 ethy1butylbicyclo[3.2.01heptan 6-y1)ethylenedioxydiacetate.

Groggins: Unit Processes in Organic Synthesis (New York, 1952), pages 607-611.

Peterson et al.: Ind. Eng. Chem, vol. 52, pp. 807-8 (1960).

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION BEST AVAILABLE COP Y December 10, 1963 T AVAILABLE COPY tent No. 3, 113,963

John R. Caldwell et a1.

It is hereby certified that error appears in the above numbered patit requiring correction and that the said Letters Patent should read as Jrrected below.

Column 1 line 20, for "celllulose" read cellulose Lnes 65 to 72, for that portion of the formula reading at d on 2 l 2 olumn 2, lines 48 to 56, for that portion of the equation eading :olumn 5, lines 36 and 37, for "7 7dimethylbicyclo[3.2.0]heptat- 5-01" read 7, 7-dimethy1bicycl0 [3.2.0]heptan-6-o1 column 6, line 31 for "7,7-methy1ethy1bicylo[3.2.0]heptan-6-ol" read 7,7-methy1ethylbicyclo[3.2.0]heptan-6-ol same column. about lines 53 to 59, the formula should appear as shown below instead of as in the patent:

I +2 H O CH CHC-C H C H -C CH CH C 119 C H9 column 7, lines 25 to 30, for that portion of formula 1 reading I] l R read R column 8, lines 16 and 17, for "Bis("(' 7-d imethylbicycle[3.2.0] hep tan6-yl)0xydiaceta te" read Bis(7,7-dimethylbicyclo [3,2,0]-

heptan6yl)oxydiacetate Signed a nd sealed this 30th day of June 1964.

(SEAL) Attest: ERNEST w SWIDER EDWARD J, BRENNER Attesting Officer Commissioner of Patents 

1. A DIESTER OF (A) AN OXYDICARBOXYLIC ACID OF THE FORMULA 